The monitoring of bovine pregnancies derived from transfer of in vitro produced embryosMarcel A.M. Tavernea, Simone P. Breukelmana, Zsolt Perényib, Steph J. Dielemana, Peter L.A.M. Vosa, Herman H. Jonkera, Lisette de Ruighc, Jannecke M. Van Wagtendonk-de Leeuwc and Jean-François Beckersb
a Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
b Department of Physiology of Reproduction, Faculty of Veterinary Medicine, University of Liège, Belgium
c Holland Genetics, R&D, Arnhem, The Netherlands
Both an increased rate of embryonic, foetal and perinatal losses, and the occurrence of deviations in foetal and placental development are associated with bovine pregnancies obtained from in vitro produced embryos. This thus requires for a more accurate and frequent monitoring of foetal and maternal functions during pregnancies. Such approaches will enable to establish the period during which these losses and deviations in development occur and to plan possible clinical interventions. This paper reviews some recent data on return rates, late embryonic and foetal losses in recipients after the transfer of either MOET, IVF or nuclear transfer embryos. Special attention is paid to the diagnostic value of measurements of pregnancy specific/associated proteins and progesterone in maternal plasma. Possibilities to measure foetal body sizes, size of placentomes and foetal heart rate by means of transrectal or transabdominal ultrasonography are illustrated with data from the literature and with recent results from our own large field study with MOET, IVP-co-culture and IVP-SOF embryos.
Key words: cow / pregnancy / pregnancy proteins / ultrasonography / foetus / placenta / foetal heart rate / embryo transfer / in vitro fertilization / nuclear transfer
Correspondence and reprints: Marcel A.M. Taverne
© INRA, EDP Sciences 2002